Tools you will need

DO NOT just tighten your seatclamp bolt up to a ridiculous degree. That won’t work and it will damage your post and possibly your frame.

Essentially the answer is to take everything apart, clean it all properly and re-assemble using the appropriate substance.

Well, you should check that your seatpost is the correct size for your frame first. It’s highly unlikely that the post will be undersized but it’s worth a quick check – especially if the bike is secondhand.

Take the seatpost out of the frame. Clean and degrease all the old grime off it.

Remove the seatclamp from the frame. Take the bolt(s) completely out of it. Clean and degrease all the old grime off everything.

Grease the seatclamp bolt(s) and reinsert them into the clamp. For alloy frames and posts put some anti-seize compound on the inside of the clamp before putting it back on to the frame. For carbon frames and posts don’t put anything on the seatclmap.

DO NOT use grease on carbon seatpost or frames. Carbon will absorb the grease and swell up and you’ll have to bin your bike. Not good.